Deuteronomy 8:8 contains the biblical enumeration of the shivat haminim — the seven species with which the land of Israel is blessed: wheat, barley, vine, fig, pomegranate, olive, and honey (date or bee honey, depending on interpretation).
זית (Zayit, "olive") is the seventh. Its oil anointed kings and priests, fueled the menorah, and symbolizes peace from the branch the dove brought to Noah.